Mulching of cut grass, clippings and vegetation has significant ecological benefits. Heretofore, it has not been possible to effectively mulch grass clippings and the like with conventional lawn mowers for several reasons. Lawn mowers typically include a predetermined number of wheels to support the mower a predetermined distance above the ground. The mower housing is typically adjustable to select the desired height of the cutting blade to effect the desired cut. The wheels make it difficult to maneuver the lawn mower around obstacles and to otherwise turn the mower. Self-propelled rotary lawn mowers remove some of the labor involved in moving the mower around the lawn, but considerable effort is still required to guide and turn such mowers
It is also known in the prior art to provide wheel-less grass cutting apparatus, which have a power-operated rotary cutter and commonly-driven air impelling means for causing air to be introduced into the mower housing and directed downwards toward the ground. This operation produces a reaction force with the ground (the so-called "ground effect"), thereby supporting the mower a small distance above the ground on a cushion of air.
Prior-art "air-cushioned" lawn mowers have several disadvantages which make them difficult to use for grass cutting, let alone mulching of such cuttings. Such mowers typically have a narrow bottom surface or border in facing relationship with the ground. During operation, air blown toward the ground by the air impelling means tends to escape from the housing between the ground and the bottom surface, which substantially reduces the lifting force. The rapid escape of air along the periphery of the mower housing also stirs up dust and debris when mowing around shrubbery and the like, which makes mowing difficult and hazardous. Also, because the air is blown downward to keep the housing afloat, the air pressure depresses the grass, causing the cutting blade to leave an uneven cut. Other problems associated with prior-art air-cushioned lawn mowers include the problem of maintaining the mower on a straight cutting path and keeping the mower housing level. Further, such mowers do not an effective means to discharge grass cuttings.
It would therefore be desirable to provide a wheel-less or air-floated lawn mower that has the capability of mulching grass cuttings and that overcomes the other problems associated with prior art air-floated devices.